Two UN agencies are issuing warnings that industrial pollutants, degradation of the ozone layer in the earth's stratosphere, and the misguided behavior of sun seekers have created a growing worldwide public health hazard. The occasion is this week's UN-declared International Day for the Preservation of the Ozone Layer. RFE/RL discusses the problem with both the World Health Organization and the United Nations Environmental Program and finds that the only sure agreement is that there is a problem.

Prague, 17 September 2003 (RFE/RL) -- The World Health Organization (WHO) says melanoma and other skin cancers kill 66,000 people a year around the world. The WHO says physicians record 130,000 new skin cancer cases a year.

On the occasion of this week's UN-declared International Day for the Preservation of the Ozone Layer (16 September), WHO Director-General Lee Jon-Wook said a significant cause of the problem is increased human exposure to harmful ultraviolet (UV) rays -- that is, radiation from the sun. This is due, he said, to degradation of the ozone-layer shield in the earth's stratosphere.

Scientific concern over damage to the ozone layer dates from the 1970s when three prominent scientists recognized that industrial pollutants discharged into the earth's atmosphere could make their way into the stratosphere and deplete the ozone there. The ozone layer screens out much of the sun's harmful UV radiation.

In the U.S. Congress last month, prominent conservative lawmakers objected to an international campaign to reduce emissions of pollutants, especially in industrialized nations, in order to lessen the ozone-layer damage. They said the campaign demanded destructive economic costs based on what they called "spurious science."

In 1995, the Royal Swedish Academy of Sciences awarded the Nobel Prize for Chemistry to the three scientists who first sounded the alarm.

Last week, Jonathan Shanklin of the British Antarctic Survey (BAS) was quoted by Reuters news service as saying that a threatening hole in the ozone layer of Antarctica hit record proportions in August and was likely to get bigger.

Also last week, Deutsche Presse Agentur quoted Shanklin's BAS colleague Alan Rodger as saying the rate of change in the ozone layer is slowing, a cause for optimism. Neither BAS scientist was immediately available to explain, but other environmentalists said the comments only appeared contradictory. The difference in emphasis was due to different focuses -- one on short-term meteorological effects, the other on longer-term trends.

The various attitudes, however, do spotlight the complexity of the issues of health, industrial development, economics and environmental protection. About the only sure point of agreement among the interests involved is that there is a problem.

On the occasion of yesterday's International Day for the Preservation of the Ozone Layer 2003, the WHO and the UN Environmental Program (UNEP) announced an ambitious educational campaign to persuade children around the world to treat with caution their time in the sun. This, of course, has to do with preserving human health and is only tangentially related to preserving the ozone layer.

Our correspondent asked Eva Rehfuess, a WHO environmental health scientist in Geneva, how we can be sure that the diminished ozone layer is a root cause of UV-related diseases. Her answer: We can't.

"Well, we know that skin cancer rates, both melanoma and nonmelanoma skin cancer, have been on the rise over recent decades. And it is probably mostly due to changes in people's behavior. People are now actively seeking the sun," Rehfuess said.

A hundred years ago, Rehfuess theorized, pale skin was a badge of status. A browned face suggested that its owner was a farm hand, fisherman, or other worker in the outdoors. It was only during the 20th century that a tan became associated with prosperous leisure and fun in the sun.

Leo Heileman is a policy manager in UNEP's division of technology, industry, and economics. The same data leads him to a different conclusion. "With the global depletion of the ozone layer of about 4 percent as well as large variations in different parts of the world, direct monitoring of UV radiation has shown a direct increase in relation to the reduction of the ozone layer," he said. In other words, measurements show that whenever and wherever the ozone layer gets thinner the level of UV rays reaching the earth gets higher.

Heileman said further, "And now the relation between the increase of these types of diseases -- nonmelanoma and melanoma skin cancer -- as well as eye cataracts also shows a direct relationship, correlation, with the increased level of ultraviolet light."

Both points of view can be right in part, of course.

The UNEP and the WHO jointly announced a worldwide campaign to persuade their various national constituencies -- ministries of education, health, and the environment -- to implement an international education program to teach children to respect the hazards of the sun.

The message, say the two agencies, is that sunlight is necessary to good health but that too much sun can kill. They are urging people, especially children, to avoid the sun at peak times of day and to avoid overexposure and sunburn generally. They hope to popularize hats and other protective clothing. They seek to associate signs of carefulness in the sun with smartness about health.

The WHO's Rehfuess said there's good reason to target children. "[There] are a number of epidemiological studies that show that if you are exposed to high levels of UV radiation in childhood, you have a much higher risk of developing skin cancer later in life," she said. "This does not mean that we as adults do not have to have to look after ourselves any more, but exposure during childhood is probably the most important, the critical period, that we need to tackle first."

But slowing ozone depletion remains a global challenge. On the same day last month that the U.S. Senate voted to delay action on proposed legislation to restrict pollutants from automobiles, the U.S.-based "Journal of Geophysical Research" published what it said is the first evidence that global cooperation on the atmosphere is effective. It said researchers have found that a slowing of the destruction of the ozone layer coincides with a worldwide reduction in chlorofluorocarbons that began in 1989 with an international treaty known as the Montreal Protocol.

Head researcher Michael Newchurch, a scientist at the University of Alabama, said the findings are proof that those early steps are working.